Earth probing radar system
First Claim
1. A method for determining condition and homogeneity of the structure of coal seams, comprising:
- transmitting pulsed electromagnetic energy into the face of a coal seam;
receiving said energy transmitted into said face to develop a return signal per transmitted pulse;
processing selected successive return signals to eliminate source coherent interference while increasing the signal to noise ratio; and
indicating visually any structural inhomogeneities within said coal seam.
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Accused Products
Abstract
A ground probing radar method and apparatus which is effective to view the earth in advance of coal mining activity provides visual display of a coal seam and particular discontinuities that may lie therein. The system operates in the frequency range of 10 Megahertz to 5 Gigahertz. The received electromagnetic energy is amplified, sampled and band pass filtered with subsequent time gain amplification. A time analog return signal may be viewed directly and/or the return signal may be digitally processed to enable further signal refinement. A control microprocessor is utilized for both tape record control and digital signal processing, and the processor includes the capability for compositing and/or stacking of common source point data for output record and display.
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Citations
30 Claims
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1. A method for determining condition and homogeneity of the structure of coal seams, comprising:
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transmitting pulsed electromagnetic energy into the face of a coal seam; receiving said energy transmitted into said face to develop a return signal per transmitted pulse; processing selected successive return signals to eliminate source coherent interference while increasing the signal to noise ratio; and indicating visually any structural inhomogeneities within said coal seam. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for determining condition and homogeneity of earth structure proximate coal deposits, comprising:
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forming at least one borehole of selected attitude through said earth structure; transmitting pulsed electromagnetic energy into the wall of said at least one borehole at a selected position therealong; receiving said energy transmitted into said wall to develop a return signal per transmitted pulse; processing selected successive return signals to eliminate source coherent interference while increasing the signal to noise ratio; and indicating visually any structural inhomogeneities within said earth structure. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. Apparatus utilizing radio energy for determining the character of earth structure, comprising:
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transmission means including directive antenna energized at a selected repetition rate for propagating pulsed radio energy into an earth structure at an exposed face thereof; receiver means including antenna for receiving the reflected radio energy from said earth structure; means enabled at said repetition rate to generate a non-linear sampling rate; means amplifying and sampling the reflected energy signal at said non-linear rate to provide a reduced frequency receiver signal; means for selective band pass filtering and time gain amplification of said receiver signal to generate a time analog return signal; means selectively operable to receive input of said time analog return signal for analog to digital conversion and time coincident signal compositing to produce a digital return signal; and means for recording and displaying the selected one of said time analog and digital return signals with enhanced rejection of both random and source coherent noise.
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24. Apparatus utilizing radio energy for determining the character of earth structure, comprising:
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transmission means including directive antenna for propagating radio energy pulses at a preset pulse repetition frequency into an earth structure exposed face in at least one source position; receiver means including antenna for receiving pulse radio energy in at least one receiver position in said earth structure; means for amplifying the received radio energy signals to produce a return signal for each transmitted pulse; means for generating a real time ramp voltage at the pulse repetition frequency with ramp duration at a preselected time window length; scan ramp generator means including a multiplexing digital to analog converter for generating a scan ramp voltage at a preselected submultiple of said pulse repetition frequency; means comparing said real time ramp voltage and said scan ramp voltage to generate a plurality of sample rate pulses; sampling means receiving said amplified return signals and responsive to said sample rate pulses to generate a return trace output; recorder and display means; and microprocessor means receiving said return trace and providing data output in record format to said recorder and display means. - View Dependent Claims (25, 26, 27, 28, 29, 30)
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Specification